Camera assembly for photographing cavity walls



Jan. 26, 19-54 R. e. PIETY 2,667,109

CAMERA ASSEMBLY FOR PHOTOGRAPHING CAVITY WALLS Filed on. a, 1950 2Shefi-Sheet 1 \x xxxx \k IX x 3B INVENTOR.

R.G.PIETY FIG. 3. ATTORNEYS 2 Sheets-Sheet 2 R. G. PlETY F/G. 2C.

INVENTOR. R c. PIETY ATTORNEYS CAMERA ASSEMBLY FOR PHOTOGRAPHING CAVITYWALLS Jan. 26, T954 Filed Oct. 9, 1950 FIG. 28.

F'atented Jan. 26, 1954 CAMERA ASSEMBLY FOR PHOTOGRAPHING CAVITY WALLSRaymond G. Piety, Bartlesville, kla., assignor to Phillips PetroleumCompany, a corporation of Delaware Application October 9, 1950, SerialNo. 189,185

8 Claims.

This invention relates to a camera adapted to take a picture of a wallof a cavity. In one of its aspects, it relates to a bore hole cameracapable of taking a plurality of pictures vertically of the formationspenetrated by a bore hole which contains a fluid. In another of itsaspects, it relates to a means for removing opaque fluid from theposition between a bore hole camera and the walls of the bore hole.

In the prior art, there have been disclosed bore hole or cavity cameraassemblies which employ a rigid transparent window formed from suchmaterials as glass or a transparent plastic through which the wall of abore hole or other cavity is viewed by the cameras optical system whichoccupies a fixed position opposite such window. The transparent windowis ordinarily of great thickness to withstand the high pressuresencountered in a bore hole and the problem of sealing the juncture ofsuch window with the camera casing against leaks of fluid into thecamera itself has been particularly difficult. In addition, such a borehole camera views only a few inches of vertical distance along the borehole wall when in any given position; and in order to take a pluralityof pictures or the walls of a bore hole, it is ordinarily necessary toraise or lower the entire bore hole camera assembly by means of a cableto succeedingly adjacent positions in order to obtain a verticalpanoramic view of the walls of the bore hole. Obviously, such means ofraising or lowering of the bore hole camera assembly makes it dimcult toaccurately position the camera in order to take succeeding pictureswhich are correctly spaced apart. Still further, many bore holes orother cavities contain an opaque fluid such as drilling mud which mustbe removed in order to permit the camera to take pictures of the borehole walls. In the prior art, the removal of such opaque fluid hasordinarily been accomplished by packing off a suitable length of borehole above and below the camera and then removing the opaque fluid fromthis packed-oi? region by displacing it with clear water pumpedthereinto. Obviously, such a procedure entails cumbersome equipment,such as packing rings, which is diflicult to correctly position in thebore hole.

According to this invention there is provided a camera assembly capableof taking pictures of the walls of a bore hole or other cavity, such asthe gastral tract of the human body, wherein any opaque fluid which mayexist between the camera and the walls of the bore hole or cavity isdisplaced therefrom by a flexible transparent diaphragm or membrane,such as a rubber membrane. In general, the camera assembly or toolincludes a container, such as a tube, which can be lowered into the borehole or other cavity and which can be filled with clear water from asource at the working surface of the cavity or from any other source. Awindow is cut from the wall of the container or tube and the camera andfilm are located inside the tube opposite the window therein. The windowis covered by a flexible, transparent diaphragm or membrane throughwhich the camera is adapted to take pictures of the wall of the borehole or cavity lying on the opposite side of said diaphragm. Further,the diaphragm is expansible by means of pressure applied by the watercontained in the tube so that it can be expanded outwardly from the tubeto press against the wall of the bore hole thereby displacing any opaquefluid from between the cameras optical system and the wall of the borehole. When the transparent diaphragm becomes stretched, it becomestransparent and serves as a window through which the pictures are taken.The transparency of the diaphragm is higher in Water and other liquidsthan in air, since the interfacial change in refractive index is muchsmaller. The filling of the tube of water also serves to keep the filmand the camera cool so that pictures may be taken in bore holes whereinthere exists temperatures which would ordinarily be too high for usewith ordinary photographic film. A spring biasing means is mounted onthe tube opposite the diaphragm-covered window to push the window sideof the tool against the bore hole wall. Inside of the tube is the cameraproper which, as stated, is surrounded by water. A means is provided tomove the optical assembly of the camera along the diaphragm-coveredwindow while maintaining the film stationary in position to thereby takea plurality of pictures of a vertical section of the formation withoutmoving the entire camera or tool assembly.

It is an object of this invention to provide a camera capable of takinga picture of the wall of a bore hole or other cavity and which isespecially adapted to force any opaque fluid between said camera andsaid walls from between such space.

It is another object of this invention to provide a camera capable oftaking a plurality of pietures of the walls of a bore hole or othercavity Without moving an entire camera assembly upwardly or downwardlyin the bore hole while taking such pictures.

Still another object of this invention is to provide a means fordisplacing an opaque fluid from phragm adapted to be pushed against thewalls of the bore hole to thereby replace .theopaque fluid therefrom.

Other objects and advantages of this invention will be apparent to oneskilled in'the art upon consideration of the disclosure contained hereintaken in conjunction with the attached drawings wherein Figure 1represents a view-of the camera asembly or tool of this inventionlowered inside of a bore hole and wherein Figures 2A, 2B,-2C'and 3represent the detailed drawings of the internal apparatus of the borehole camera assembly of this invention. Figures 2A, 2B and 20 togetherconstitute a single partial-cross-section of the;apparatus of thisinvention. Figure 2B is joined at the top by Figure 2A and at the bottombyFigure 20.

In Figure 1 the bore hole camera assembly is shown inside of a bore holeI having walls 2. The camera assembly includes a container which can bean elongated tube 3. section of pipe of sufiicient length to contain thenecessary equipment which will be described hereinafter. A lowering tube3A or other means such as a cable can be provided to lower and positiontube 3 in bore hole i. A water supply pipe 33 can be provided throughwhich water can be pumped from the surface of the well to the interiorof tube 3'. The upper and lower ends of tube 3 are sealed by plates tand 5 to prevent intrusion of fluids from the bore hole into the tube.The ends of the tube 3 have slots 6 and l therein adapted to receivevertically slideable yokes 8 and 9. Slots 8 and l are recessed in tube 3but do not extend completely therethrough. The external ends of yokes 8and 9 are joined by a flexible member, such as spring 13, which is soconstructed as to tend to cause yokes (l and 9 to move along slots 6 andTin a direction toward each other. In this manner, when tube 3 islowered into the bore hole, spring to pushesagainst one wall of the borehole thereby forcing tube .3 against the opposite wall of the bore hole.As irregularities of the wall of the bore hole are encountered, sprin 10flexes yokes 8 and 9 along slots 8 and 7 thereby maintaining tube 3snugly in a position against the wall of the bore hole. The length ofslots 6 and l is such that either yoke 8 can be pushed to the low-er endof slot 6 or yolze t can be positioned at the upper end of slot 71',while the other yoke is being moved along the length of its slot topermit spring in to freely flex according to the contours of the borehole. Thus, for example, when yoke 8 is positioned in the lower end ofslot 6, slot i is long enough to permit yoke 9 to slide freely thereinirrespective of the extent spring Iii is compressed or extended inaccordance with the contour of the bore hole walls. Alternatively, yoke9 can be positioned at the upper end of slot 1 without causing yoke 8 tocontact either end of slot 8 as spring it is flexed by the walls of thebore hole. In this manner, only one of yokes t or 9 can move to permitspring if! to be freely flexed while the other yoke remains in a fixedposition at the upper or lower end of its slot.

Tube 3 can be a Such an arrangement permitsv 4 tube 3 to be readilymoved upwardly or downwardly in the bore hole without binding. Forexample, when tube 3 is being lowered in the bore hole, spring in andyokes 3 and s will be pulled upwardly by friction with the wall of thebore hole along the length of tube 3 until yoke Q seats at the upper endof slot l. While yoke 3 is in this position, yoke 8 will be free to movealong slot 5 thereby allowing spring is to flex.

Referring more particularly to Figures 2A, 2B,

2C and 3, tube 3 has a portion of its circumfere ence :removed to form awindow opening H.

Surrounding window opening I l is a flexible diaphragm I2 which can becomprised of a thin sheet of transparent :material such as white rubber,

Pliofilm, cellophane and the like. The transparent material should besufficiently transparent when immersed in water to permit a picture tobe takentherethrough. Flexible diaphragm i2 is attached to tube 3 by anysuitable mean but preferably is cemented to cleats l3 and i l. Flangesl? and i8 can be provided to prevent tube 3 from approaching too closelyto the walls of the borehole and thereby provide a suitable focaldistance between the optical apparatus of the camera and the walls ofthe bore hole. As shown, flanges ii and i8 are formed to have a lipwhich extends from the wall of tube 3 to rest against the walls of thebore hole. Such flanges can be suitably shaped to prevent anyundesirablegouging into the walls of the bore hole.

Inside of tube 3 and adjacent window it there are provided film supportsit and as which are;

adapted to hold film 2! in a fixed position with respect to window ii.Film supports it and can comprise any suitable type of bracket adaptedto hold the film. For example, they can be a pair of slotted membershaving a plane surface attached therebetween adapted to support thefilm. Alternatively, film 2! can be mounted in a conventional cut-filmholder which is fixedly attached to the inner walls of tube Tube 3 canhave a removable section 2 5A therein to provide a ready access forreplacing film H with fresh film after it has been exposed.

The optical assembly can comprise a light source 22 which can be anysuitable type of light adapted to provide sufficiently strong light toenable the film to be exposed. Light source .22 can be anordinary lowvoltage light bulb such as a 6 volt, 3 candlepower bulb. Alternatively,light source 22 can be a stroboscopic light capable of delivering a peakillumination of at least a million lumens for a period of approximately,3 second. A source ofenergy (not shown) for energizing light source 22can be provided in the upper portion or" tube 3 and connected thereto bymeans of suitable wires which can be situated in grooves (not shown) inthe wall of tube 3. A switch for controlling the energization of lightsource 22 can be located at the upper end of the borehole. Light source22 is attached to a slide-able support 23 in such a fashion that lightis directed outwardly asshown to pass through diaphragm l2 and to thenbe reflected by the wall of the bore hole which it is desired tophotograph. A. plane mirror 2! is attached to support 23 in suchposition as to receive the light reiiected from light source 22 by theportion of the wall of the bore hole which it is desired to photograph.A concave mirror 25 is attached to support 233 to re ceive the lightreflected from plane mirror 2-; and-an additional plane mirror 26 islikewiseattached tosupport 23 to receive the reflected light fromconcave mirror 25 and to reflect such light onto film 2 I. Light source22 and mirrors 24, 25, 23 are all maintained on support 23 in a fixedposition relative one to the other and are adapted to be moved withsupport 23 downwardly with respect to the surface of film 2! whichremains in a fixed position.

As shown in Figures 2A, 2B, 2C and 3, support 23 is adapted to slideinside of tube 3 and can be so shaped that its outer surface acts as abearing surface against the inner surface of tube 3. If desired,suitable means, such as roller bearings, can be positioned betweensupport 23 and tube 3 to provide a maximum ease of slideability ofsupport 23 along tube 3.

A bafile 27 is attached to support 23 as shown to prevent stray orincident light from light source 22 from striking film 2|. The bafilecan comprise a sheet or plate of opaque material having an openingtherein sufiiciently large to permit the reflected light from mirror 26to pass therethrough onto film 2|.

An optical system positioning means is provided in the upper portion oftube 3. Such means can comprise a solenoid 28 operatively connected bymeans of core 29 carrying a pin 30 sliding in slot 3| to a ratchet 32.Core 29 is adapted to be moved upwardly when solenoid 28 is activated bya source of energy (not shown) which can be located at the surface ofthe bore hole. Core 23 can also be biased downwardly with respect tosolenoid 28 by means of a suitable spring 33. Ratchet 32 is pivotedabout axis 33 which is mounted on support 34 attached to the casing ofsolenoid 23. A support member 35 is employed to connect solenoid 23through support 34 to support 23. Attached to the wall of tube 3adjacent to ratchet 32 is a notched track 33 which has a plurality ofnotches 31, 38, 39, etc., recessed therein to receive the tooth ofratchet 32. Notches 37, 33, 39, etc., are spaced apart a distance equalto the length of the successive exposures desired upon film 2|. Abiasing means, such as a spring 30, can be provided to urge solenoid 23and all elements dependent therefrom downwardly through tube 3.Alternatively, solenoid 28 and ratchet 32 can be attached to tube 3 andtrack 36 made slideable therealong and attached by a support to support23.

In operation, the camera assembly is lowered in the bore hole to aposition such as that shown in Figure 1. Water is then pumped throughpipe 313 into the inner portion of tube 3 from a source in the surfaceof the bore hole to thereby cause flexible window I2 to be extendedagainst the walls of the bore hole. Alternatively, water can be pumpedfrom a reservoir (not shown) in tube 3 by an electrically driven pump toextend window 12. In so doing, any opaque fiuid between the walls of thebore hole and the camera assembly will be displaced by the extension ofthe flexible diaphragm so that any light emitted from light source 22will pass through clear water inside of tube 3 and not be absorbed byany opaque fluid which had theretofore existed along the bore hole.Spring It bears against one wall of the bore hole and acts to pull yokes8 and 3 together along slots 6 and 1 thereby forcing the camera assemblyin tube 3 against the opposite wall of the bore hole as shown inFigure 1. When the camera assembly has been so positioned, the switch atthe surface of the bore hole can be thrown to connect light source 22with its source of energy so that it will be lighted to expose asuitable portion of film 2! to an adjoining portion of the bore holewall. The time of exposure notches in track 33.

can thus be readily controlled. Then, in order to move the opticalsystem to expose a new portion of film 2|, solenoid 28 can be energizedto retract core 29 into the solenoid thereby disengaging ratchet 32 fromnotch 37 of track 33. The optical assembly, as well as solenoid 23 andratchet 32, will then slide downwardly along track 36 along the insideof tube 3. Immediately after ratchet 32 has been disengaged from notch31, the source of energy at the surface of the bore hole is disconnectedfrom solenoid 28 whereby ratchet 32 is pushed laterally by the spring insolenoid 28 which biases core 23 downwardly. When the entire opticalassembly has been lowered sufficiently, the engaging tooth of ratchet 32will engage notch 38 in track 36 thereby stopping further lowering ofthe optical assembly. The source of energy at the surface of the borehole can again be connected to light source 22 thereby exposing thesucceeding portion of film 2! to the next lower portion of the bore holewall viewed by the optical assembly.

Thus, a series of pictures can be made of the walls of a bore holewithout moving the entire camera assembly since only the opticalassembly moves downwardly while the film remains stationary. If desired,only a portion of the available exposures on film 2i can be taken at anyone position of the camera assembly. The entire camera assembly can thenbe lowered after removing a portion of the water contained in tube 3 tothereby collapse diaphragm 82.

When it is desired to expose the entire length of film 2i when tube 3 ispositioned at a single location, track 36 can be replaced with a rackand solenoid 28 and ratchet 32 can be replaced with a pinion gearconnected to an electric motor in such a manner that the motor can drivethe optical assembly continuously along film 2 E. When so operating witha low energy light source such as the 6 volt bulb described above, thelight can be permitted to burn continuously to expose film 2| as it ismoved therealong. When light source 22 is comprised of a stroboscopiclight as described, a switch can be attached to the moving opticalassembly to be actuated by tripping projections mounted on a tracksimilar to the When the image is not magnified by the optical system,the movement of the optical system past film 2i will not blur the imagecast thereon even though the light source is burned continuously.

As stated, the camera assembly of this invention is particularly adaptedto be employed in regions wherein such high temperatures exist that anegative material could not ordinarily be employed. In the instantcamera, the water employed to force diaphragm i 2 against the bore holewall cools the negative or film thereby preventing damage by heat. It isoften desirable to circulate water in through pipe 3B into tube 3 andthence out tube 3A to provide adequate cooling of the film. Tube 3Bshould extend to lower end of tube 3 to provide a positive circulationof water around film 2i. Suitable dyes can be dissolved in the water toprovide any desired filter eifects for the film. If desired, pipe 33 canbe omitted and water can be circulated through tube 3 by means of tube3A. An orifice of suitable size or other fiow regulating means can thenbe provided to permit the escape of water from tube 3 into the borehole. The desired pressure can be exerted in tube 3 by regulating therate at which water is passed through tube 3A into tube 3.Alternatively, tubes 3A and 33 can be 7, aplaced by a reservoir ofwate'r"'situate'd in apoi .on of tube 3-, which water can be circulatedin she 3 by a pump actuated by-an electric motor.

One of the advantages derived from employing he camera assembly ofthisihvention-is that it an be employed in regions of high pres'suresuch us those existing at the bottom of a w'elbfill'ed vith adrillingmud or other-opaque material; thus, the water passed into tube 3can be under t pressure which is only slightly'higher or lower han thatof the welland; therefora-it is not iecessary thathigh-pressure'fittings be employed 2o prevent seepage of theopaque'fi'uidinto the .nterior of tube 3.

Although one type of optical system has' be'en shown, it is obviousthat'other opticalsystems :an be devised without departing from' thescope of this invention. In any: such optical system;- the image ispreferably" neither magnified nor reduced in size while being. reflectedonto the film. Also, it is" preferred that' the'image be reflected ontothe film in-the correct position, i. e., not inverted.

The camera assembly of'thisinvention can'be suitably adapted to beemployedfor'photographing the walls of different types of cavities, suchas those existing in the human or in animal bodies. It can also beemployedtophotograph' the walls of a vessel containing an opaque fluid.

When it is desired to photogramh an object existing in a clear fluidsuch as sea-water, diaphragm iii can be omitted from'thecameraassemblyof this invention and the photograph can be taken through the clearfluid then existing around the camera assembly without displacing suchfluid with a clear fluid coac-tingwith diaphragm 12 as disclosed above.Insuch case,

the camera assembly can comprise-film 2 laihxedto a support such as tube3 and-the optical assembly which includes light source 22-and-a lighttransmitting means, such as mirrors 24; 25, and 2.5. Also, a means formoving such optical-assembly along film 2! should be included and suchmeans can comprise ratchet 32 and an actuating mechanism such assolenoid 2-8 as above described.

While the invention has beendescribedin connection with a present,preferred embodiment thereof, it is to be understood that thisdescription is illustrative only'andis not'intendedto limit theinventiomthe scopeof which is defined by the appended claims.-

I claim:

1. A camera assembly adapted to photograph the wall or" a cavitywhich-compriseain combination, a fluid-tight tube having a portion ofits wall removed to form an opening. therein,-a-

transparent flexible diaphragm-attached to said tube and extendingacross said opening, means for introducing and withdrawing water fromthe interior of said tube diaphragm against an adjacent 'wall of saidcavity to be photographed, a

said optical assembly comprisinga light source capable or" periodicallyflashing to expose said film, a plane mirror adapted to receive lightwhich is reflected from said light source by said wall of said cavity tobe photographed and to reflect said light to an image focusing concavemirror, a second plane mirror adapt'edto receive light reflected fromsaid concave mirror and to reflect said light-onto said film to form aphotographic image thereon, a baffle situatedbetween to thereby extendsaidphotographic film V mounted inside said tube oppositesaid opening,an optical system movable parallel to saidfilm said light source andsaid filmto preventany light-from said source except said reflectedimage from' striking said film, a means for moving and positioning saidoptical system along said film which comprises a solenoid slidablymounted in the upper portion of said tube, a notched track attached tosaid tube, a ratchet adapted to engage succeeding notches in said trackand adapted to be disengaged therefrom by movement of a core in saidsolenoid when the latter is'momentarily energized and a means forbiasingsaidtube against the wall of said cavity so that said diaphragmcan be extended to exclude any opaque fluid from the space between saidoptical system and said wall which comprises a pair of yokes eachslidably mounted in' slots located at the ends of said tube and a bowedspring member adapted to draw said yokes along said slots to'iorce saidtube against the wall of said cavity.

2. A camera assembly adapted to photograph thewall of a'cavity whichcomprises, in combinatioma' fluid-tight tube having'a portion ofits-wall repl'aeed by a transparent flexible diaphragm, means forvintroducing water into-said tube to thereby extendsaid' diaphragmagainst a wall of said-cavity to be photographed, a photographicfilmniounted inside said'-tube,an optical system movable parallel-tosaid film, said opticalassembly comprising a light source capable ofperiodically fiashing to expose said film, a plurality of mirr rsincluding an image focusing concave mirror adapted to receive lightwhich is reflected from said light source by said wall to bephotographedand to relect'said light to said film to form an imagethereon, a means for moving and positioning said optical system alongsaid: film which comprises a solenoid slidably mounted in the upperportion" of said tube, a notched track attached to said tube, a ratchetadapted to engage succeeding notches in said track and adapted to bedisengaged therefrom by said-solenoidwhen the latter is momentarilyenergized anda' means for biasing said tube against the wall ofsaidcavity sothat' said dia-' phragm can be extended'to exclude any opaqueiiuid from the spacebetween said opticalsystein and said wallwhich'comprises' a pair of yokes each slidably mounted: in slots.located at the ends of said tube and a bowedspring member adapted todraw-said yokes along said slots to force said tube against the wall ofsaid cavity.

3. A camera assembly.- adapted to photograph the wall of'a cavitywhichcomprises, in combination, a container having a portion of its wallreplaced bya transparent flexible diaphragm; means for extending saiddiaphragm against an adjacent wall of said cavity to be photographed,a'photographic film mounted inside said" container, an optical. system,including a source of cal system and said Wall which comprisesa-bowedspring member having its ends slidably connected with saidcontainer insuch manner that w the bowing of said spring member againstthe wall of said cavity forces di phragm containing wall of saidcontainer against the Wall to be photographed.

4. A camera assembly comprising, in combination, a container having aportion of its wall replaced by a transparent fl xible diaphragm, meansfor extending said diaphragm against an adjacent wall of a cavity to bephotographed, a photographic film mounted inside said container, anoptical system movable with respect to said film and adapted to transmitan image of said wall to said film, a light source movablelongitudinally with respect to said fi m, an externally operated meansfor moving positioning said optical system along said film while saidcamera assembly is in said cavity, and a for biasing said containeragainst the wall of said cavity so that said diaphragm can be extendedinto contact with said wall to exclude any opaque fiuid from the spacebetween said optical system and said wall.

5. A camera assembly adapted to photograph the wall of a cavity whichcomprises, in combination, a fluid-tight tube having a portion of itswall removed to form an opening therein, a transparent flexiblediaphragm attached to tube and extending across said opening, means forintroducing and withdrawing water from the interior of said tube tothereby extend said diaphragm against an adjacent wall of said cavit tobe photographed, a photographic film mounted inside said tube oppositesaid opening, an optical system movable parallel to said film, saidoptical assembly comprising a light source capable of periodicallyflashing to expose said a plane mirror adapted to receive light which isreflect-ed from said light source by said wall of said cavity to bephotographed and to reflect said light to an image focusing concavemirror, a second plane mirror adapted to receive light reflected fromsaid concave mirror and to reflect said light onto said film to form aphotographic image thereon, a baifie situated between said light sourceand said film to prevent any light from said source except saidreflected image from striking said film, a means for moving andpositioning said optical system along said film which comprises asolenoid slidably mounted in the upper portion of said tube, a notchedtrack attached to said tube, and ratchet adapted to engage succeedingnotches in said track and adapted to be disengaged therefrom by movementof core in said solenoid when the latter is momentarily energized.

6. A camera assembly adapted to photograph the wall of a cavity whichcomprises, in combinad-tight tube having a portion of its re, d by atransparent flexible diaphragm, means for introducing water into saidtube to thereby extend said diaphragm against a wall of said cavity tobe photographed, a photographic film mounted inside said tube, anoptical system movable parallel to said filn said optical assemblycomprising a light source capable of periodically fiashi'ng to exposesaid film, a plurality of mirrors including an image focusing concavemirror adapted to receive light which is reflected from said lightsource by said wall to be photographed and to reflect said light to saidfilm to form said image thereon, a means for moving and positioning saidoptical system along said film which comprises a solenoid slidablymounted in the upper portion of said tube, a notched track attached tosaid tube, and a ratchet adapted to engage succeeding notches in saidtrack and adapted to be disengaged therefrom by said solenoid when thelatter is momentarily energized.

'7. A camera assembly adapted to photograph the Wall of a cavity whichcomprises, in combination, a container having a portion of its wallreplaced by a transparent flexible diaphragm, biasing means adapted tomove the diaphragm containing wall of said container against the wallor" said cavity, means for extending said diaphragm against an adjacentwall of said cavity to be photographed, a photographic film mountedinside said container, an optical system including a source of lightmovable parallel to said film and adapted to transmit a photographicimage of said wall to said film, a means for moving and positioning saidoptical system along said film which comprises a ratchet and notchedtrack means adapted to fix said optical system at a plurality ofsucceeding points along said container, and means for actuating saidratchet.

8. A camera assembly comprising, in combination, a container having aportion of its wall replaced by a transparent flexible diaphragm, meansfor extending said diaphragm against an adjacent wall of a cavity to bephotographed, a photographic film mounted inside said container, anoptical system movable with respect to said film and adapted to transmitan image of said wall to said film, a light source movablelongitudinally with respect to said film, means for moving andpositioning said optical system along said film While said cameraassembly is in said cavity, and means for biasing the diaphragmcontaining wall of said container against the wall of said cavity sothat said diaphragm can be extended into contact with said wall toexclude any opaque fluid from the space between said optical system andsaid wall.

RAYMOND G. PIETY.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,658,537 Reinhold Feb. 7, 1928 1,727,495 Wappler Sept. 10,1929 2,185,508 Kunze Jan. 2, 1940 2,190,901 Wilcox et a1 Feb. 20, 19402,259,084 Rosenhaft Oct. 14, 1941 FOREIGN PATENTS Number Country Date502,331 Great Britain Mar. 15, 1939

